Line estimation, i.e., the determining of one or more characterizing properties of a transmission medium, is important in order to locate and identify problems in the transmission medium, including sheath faults, broken conductors, water damage, loose connectors, crimps, cuts, smashed cables, shorted conductors, and a variety of other faults. Herein, the term transmission media comprises all types of twisted pair and coaxial cables, both aerial and underground, as well as other types of wire-like transmission media used for conveying communication signals.
One key type of characterizing property determined through line estimation comprises characteristic impedances of different sections of the transmission medium.
Time domain reflectometry, TDR, is a method conventionally applied to determine transmission medium properties. In TDR, rectangular pulses, step impulses, pseudorandom sequences or signals generated in frequency domain are transmitted on a transmission medium, whereupon reflected signals are analyzed in order to locate and identify problems in the transmission medium. However, TDR as applied today is associated with some limitations. For instance, determining cable loops, i.e., locating and characterizing loop components of the transmission media, such as their length and respective electrical parameters, is a challenging task, mainly due to computational burden and difficulty in obtaining sufficient accuracy in the end result.
The ever increasing demand for data transmission rate and capacity drives communication systems towards increased communication bandwidth. In order to ensure reliable operation according to current and future technical standards and regulations, monitoring and diagnostics of deployed networks becomes increasingly important. However, in current line estimation methods, increasing center frequency and frequency bandwidth imply an increase in data processing requirements, leading to increases in processing time, hardware requirements, and energy consumption.
Thus, there is a need for new line estimation methods that are reliable, fast, support high bandwidth transmission media, and which are inexpensive in terms of computational load and data processing requirements.